Method and apparatus for communicating in a MMwave system via auxiliary low frequency carrier

ABSTRACT

The present application discloses a method for data transmission in a radio cell of a mobile terminal. The radio cell includes an auxiliary carrier in a low frequency band and at least one master carrier in a high frequency band, the method including: the mobile terminal achieving downlink synchronization with the radio cell through the auxiliary carrier in the low frequency band, and after achieving the downlink synchronization, obtaining configuration information of the radio cell, and transmitting data by using the master carrier and/or the auxiliary carrier according to the configuration information. The present application also provides a mobile terminal. By using the present application, radio cell coverage and transmission performance may be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

The present application claims priority under 35 U.S.C. § 365 toInternational Patent Application No. PCT/KR2014/009081 filed Sep. 29,2014, entitled “MOBILE TERMINAL AND METHOD FOR DATA TRANSMISSION IN ARADIO CELL THEREOF”, and, through International Patent Application No.PCT/KR2014/009081, to Chinese Patent Application No. 2013-10452017.6filed Sep. 27, 2013, each of which are incorporated herein by referenceinto the present disclosure as if fully set forth herein.

TECHNICAL FIELD

The present disclosure relates to mobile communication datatransmission, and particularly to a mobile terminal and a method fordata transmission in a radio cell thereof.

BACKGROUND ART

Nowadays, with popularity of intelligent mobile terminals anddevelopment of wireless internet services, mobile data services tend tobe booming, which brings unprecedented challenges for wireless networks.To meet mobile broadband requirements, currently 4G Long Time Evolution(LTE) networks adopt various technologies such as carrier aggregation(CA), large scale MIMO, Coordinated Multi-Point (CoMP), etc. to improvewireless network capacity, and to further improve frequency spectrumeffectiveness, researches for small cells are being actively pushed.

However, since the range of carrier frequencies currently being used forwireless communication is 700 MHz˜2.6 GHz, and bandwidth of availablefrequency spectrum resources is still very limited, new technologiessuch as CA, large scale MIMO, CoMP, etc. only improve peak communicationrate of a single subscriber or frequency spectrum effectiveness of acertain cell to some extent, and in the given range of the frequencyspectrum resources, improvements to wireless network capacity arelimited, which maynot meet the increasing capacity requirement.Especially, it is predicted that compared to what it is now, by year2020, the wireless network capacity may grow 1000 times, and thecapacity requirement maynot be met by only improving the frequencyspectrum efficiency. While with the heterogeneous network architecturebeing put forward, though deployment technologies of more intensivesmall cells are still developing and the frequencies are reused by wayof increasing low power access points to improve the capacity, subjectedto influences by factors such as base station site selection, deviceinstallation, backhaul network construction, etc., costs of realizingsmall cells are very high, and to increase the capacity, simplyincreasing the number of small cell sites is not enough. To make theincrease of the capacity and the number of small cells be a linearrelation, the most important thing is to solve the co-channelinterference caused by reusing the frequencies, and being heavilydependent on high level interference elimination technologies is notwhat is expected. So only by using the small cell technology, it isdifficult to meet the increasing wireless data service requirement.Obviously, multi-dimensional capacity improvement methods are effectiveways to meet future requirements. That is, an overall capacityrequirement may be realized by way of using more small cells, improvingthe frequency efficiency, improving the frequency spectrum utilization,and introducing more frequency spectrum resources.

However, the frequency spectrum resources are rare and frequencyspectrum resources of low frequency bands are very congested (e.g., 700MHz˜2.6 GHz currently being used in wireless communication), and thereis a tendency of developing higher frequency bands. To meet therequirement of the predicted 1000 times capacity increase by year 2020,the gap of the frequency spectrum is still large. In this circumstance,people pay more and more attentions on high frequency band communicationtechnologies. Millimeter wave communication technology is a mostrepresentative high frequency band communication technology, andgenerally millimeter wave has a frequency spectrum from 26.5 GHz to 300GHz. It may be seen that, besides of frequency bands of 57 GHz˜64 GHzand of 164 GHz˜200 GHz that are susceptible to oxygen and water losses,the millimeter wave is able to provide bandwidth up to 230 GHz, which ismore than 100 times of that of the frequency spectrum resourcescurrently being used, and may meet the wideband wireless data servicerequirements more better. This is the reason why the millimeter wavecommunication is widely concerned.

However, the millimeter wave has weakness that it maynot evade. First,frequencies of the millimeter wave are higher than carrier frequenciescurrently being used for wireless communication. According to aclassical free-space path loss rule, i.e., LFSL=32.4+20 log 10f+20 log10R, where LFSL is free-space path loss represented by dB, f is acarrier frequency, R is a distance between a transmitter and a receiver,the free-space path loss that the millimeter wave with the lowestfrequency (26.5 GHz) confronts is 20 dB higher than the path loss thatthe highest frequency carrier (2.6 GHz) for wireless communicationconfronts. Therefore, if the millimeter wave is used to cover wirelesscommunication cells, the weakness will dramatically influence thecoverage of the millimeter wave cells. Besides of this, in an actualwireless communication environment, the oxygen and water in the air willabsorb energy of the millimeter wave, which further influences thepropagation distance of the millimeter wave.

An ideal method that solves the above defect of the millimeter wave isto combine the large scale MIMO technology and the beamformingtechnology. The method may concentrate energy of the millimeter wave ona very narrow weave beam so that propagation of the millimeter wave hasvery strong directivity, and during point-to-point downlinktransmission, it may guarantee better coverage. However, for a realwireless communication cell, besides of the point-to-point downlinktransmission, there is other downlink transmission dedicated formultiple users, for example, broadcast messages of synchronizationchannels, public control channels, and cells, and transmission of theinformation will aim at multiple users, but, generally, different usersmay be distributed on different locations of a cell, and a narrow bandbeam realized by beamforming may only be directed to one direction,therefore, the broadcast messages of the synchronization channels,public control channels and cells may only be transmitted by using atraditional way so as to give consideration to the users in the wholecell. Compared to that of the point-to-point downlink transmission thatuses the beamforming technology, energy of wireless signals that carrythe broadcast messages of the synchronization channels, public controlchannels and cells is more diffused so that under a same transmissionpower condition, their coverage will be smaller than that of thepoint-to-point downlink transmission signals. Realization of beamformingrelies on estimate of radio channels, while estimate of radio channelsis generally realized by using a reference signal, but during an actualcommunication process, during transmission of messages at an initialstage of establishing a connection between a wireless terminal and abase station, e.g., a first downlink message, the base station is unableto obtain information of radio channels, which will affect coverage ofwireless signals that carry the messages, however, the messages arecritical for establishing a wireless link between the terminal and thebase station.

In addition, due to restriction on sizes of mobile terminals, generally,large scale MIMO may not be performed on a terminal side. That is, scaleof an antenna array on a terminal side is far smaller than scale of anantenna array on a base station side. Therefore, during uplinktransmission, concentration degree of beams will be smaller than that ofbeams during point-to-point downlink transmission, and there is anasymmetric problem existing in coverage of uplink and downlink signals.

DISCLOSURE OF INVENTION Technical Problem

It may be seen from the above analysis that by using the large scaleMIMO technology and the beamforming technology, coverage ofpoint-to-point downlink transmission in a millimeter wave cell may beimproved. Generally, point-to-point downlink transmission carries dataservices of terminals, which occupies a main ratio of data transmissionof a cell, and the point-to-point downlink transmission needs support ofuplink transmission, while broadcast messages of synchronizationchannels and public control channels and messages at an initial stage ofestablishing a wireless link are all necessary to support running acell, if coverage of wireless signals that carry these signals islimited, it will be a bottle neck of improving coverage of a millimeterwave cell. There is still no effective ways to solve the problem.

Since the higher a frequency band is, the larger path loss attenuationis, and thus, the smaller the coverage of a cell realized by using acorresponding carrier is.

Therefore, besides of millimeter wave cells, when a cell is constructedby using other carriers on frequency bands with higher frequencies, theproblem of the coverage being reduced may also exist.

Solution to Problem

The present application proposes a mobile terminal and a method for datatransmission in a radio cell thereof, which may efficiently improvecoverage of a high frequency band cell, and further improve performanceof the high frequency band cell.

To realize the above object, the present application adopts thefollowing technical solutions.

A method for data transmission in a radio cell of a mobile terminal, inwhich the radio cell comprises an auxiliary carrier in a low frequencyband and at least one master carrier in a high frequency band, themethod includes:

the mobile terminal achieving downlink synchronization with the radiocell through the auxiliary carrier in the low frequency band, and afterachieving the downlink synchronization, obtaining configurationinformation of the radio cell, and transmitting data by using the mastercarrier and/or the auxiliary carrier according to the configurationinformation.

Preferably, the master carrier is a carrier in a millimeter wavefrequency band, and the radio cell is a millimeter wave cell.

Preferably, the auxiliary carrier is configured to bear a downlinksynchronization channel and a first broadcasting channel;

the mobile terminal achieving the downlink synchronization with theradio cell through the auxiliary carrier in the low frequency bandincludes: the mobile terminal achieving initial downlink synchronizationwith a base station of the radio cell by using a downlinksynchronization signal sent by the auxiliary carrier; and

obtaining the configuration information of the radio cell includes: themobile terminal obtaining configuration information of the radio cellborne on a first broadcast channel according to a first broadcastchannel signal sent by the auxiliary carrier; and the mobile terminalreading a second broadcast channel from the master carrier according tothe configuration information of the radio cell borne on the firstbroadcast channel, and obtaining configuration information of the radiocell borne on the second broadcast channel.

Preferably, the configuration information of the radio cell borne on thefirst broadcast channel includes information on a bandwidth of theauxiliary carrier, a system frame number of the auxiliary carrier, afrequency of the master carrier, a bandwidth of the master carrier, aradio frame structure of the master carrier, and downlink cyclic prefixlength of the master carrier; and

the configuration information of the radio cell borne on the secondbroadcast channel includes a public configuration of a soundingreference signal SRS on the master carrier and an uplink random accessPRACH configuration of the radio cell; and the PRACH configuration ofthe radio cell comprises PRACH configuration information on the mastercarrier and/or on the auxiliary carrier.

Preferably, the auxiliary carrier is configured to bear a downlinksynchronization channel, a first broadcast channel, a public controlchannel and a second broadcast channel;

the mobile terminal achieving the downlink synchronization with theradio cell through the auxiliary carrier in the low frequency includes:the mobile terminal carrying out initial downlink synchronization with abase station of the radio cell by using a downlink synchronizationsignal sent by the auxiliary carrier; and

a way to obtain the configuration information of the radio cellincludes: the mobile terminal obtaining the configuration information ofthe radio cell according to a first broadcast channel signal, a publiccontrol channel indication and a second broadcast channel signal.

Preferably, the configuration information of the radio cell includes abandwidth of the auxiliary carrier, a system frame number of theauxiliary carrier system, a frequency of the master carrier, a bandwidthof the master carrier, a radio frame structure of the master carrier, apublic configuration of a sounding reference signal SRS on the mastercarrier and an uplink random access PRACH configuration of the cell; andthe PRACH configuration of the cell includes PRACH configurationinformation on the master carrier and/or on the auxiliary carrier.

Preferably, the method further includes: when the public control channelonly existing in the auxiliary carrier, the mobile terminal in idlestatus only monitoring the downlink control channel on the auxiliarycarrier to obtain a paging message and a broadcast message.

Preferably, the first broadcast channel is a master broadcast channel,and the second broadcast channel is a common broadcast channel.

Preferably, when the mobile terminal transmits data by using the mastercarrier and/or the auxiliary carrier, a process of establishing aconnection with the base station initiated by the mobile terminalincludes:

the mobile terminal performing the uplink synchronization with the basestation by using the PRACH configuration of the radio cell, and carryingout sending and receiving of related messages during the process ofestablishing the connection, until receiving radio resourceconfiguration information specific for the mobile terminal.

Preferably, the radio resource configuration information specific forthe mobile terminal includes: SRS specific configuration information ofthe mobile terminal on the master carrier and on the auxiliary carrier,uplink control channel specific configuration information of theterminal on the master carrier and on the auxiliary carrier, and uplinkand downlink transmission channel specific configuration information ofthe terminal on the master carrier and on the auxiliary carrier.

Preferably, the mobile terminal performing the uplink synchronizationwith the base station by using the PRACH configuration of the radio cellincludes:

if the PRACH configuration of the radio cell not comprising a PRACHconfiguration on the master carrier and including a PRACH configurationon the auxiliary carrier, then the mobile terminal performing the uplinksynchronization according to the PRACH configurations on the auxiliarycarrier; and/or

if the PRACH configuration of the radio cell including the PRACHconfigurations on the master carrier and on the auxiliary carrier, thenthe mobile terminal only performing the uplink synchronization on themaster carrier or on the auxiliary carrier, or the mobile terminalselecting the master carrier or the auxiliary carrier to perform theuplink synchronization according to a current radio environment.

Preferably, the mobile terminal selecting the master carrier or theauxiliary carrier to perform the uplink synchronization according to thecurrent radio environment includes: if the current radio environmentbeing superior than a predefined threshold, then the mobile terminalselecting the master carrier to perform the uplink synchronization, orotherwise, the mobile terminal selecting the auxiliary carrier toperform the uplink synchronization.

Preferably, during a process of establishing an initial connection, acarrier that receives and sends messages related to the process ofestablishing the connection is the same with a carrier where the PRACHis located.

Preferably, when transmitting data by using the master carrier and/orthe auxiliary carrier, for downlink transmission on the auxiliarycarrier, the mobile terminal detects a downlink transmission instructionon the auxiliary carrier and transmits ACK/NACK information of thedownlink transmission.

Preferably, when transmitting data by using the master carrier and/orthe auxiliary carrier, for downlink transmission on the master carrier,

the mobile terminal detects a downlink transmission instruction on theauxiliary carrier and transmits ACK/NACK information of the downlinktransmission; or

the mobile terminal detects the downlink transmission instruction on themaster carrier and transmits the ACK/NACK information of the downlinktransmission.

Preferably, for the downlink transmission on the master carrier, whenthe mobile terminal detects the downlink transmission instruction on theauxiliary carrier and transmits the ACK/NACK information, a feedbacktime sequence of the ACK/NACK information is determined according todownlink and uplink configurations of the master carrier and theauxiliary carrier.

Preferably, when transmitting data by using the master carrier and/orthe auxiliary carrier,

for the uplink transmission on the auxiliary carrier, the mobileterminal receives uplink transmission scheduling and receives feedbackinformation of the uplink transmission on the auxiliary carrier; and/or

for the uplink transmission on the master carrier, the mobile terminalreceives the uplink transmission scheduling and the feedback informationof the uplink transmission on the master carrier.

Preferably, the master carrier of the radio cell includes at least onecontrolling master carrier and at least one controlled master carrier;

a radio frame structure of the controlling master carrier includesdownlink sub-frames and configurable sub-frames; the configurablesub-frames including a special downlink time slot, a guard time slot,and an uplink pilot time slot; and

all sub-frames in a radio frame structure of the controlled mastercarrier are uplink sub-frames, or the controlled master carrier has adownlink and uplink time division duplex radio frame structure.

Preferably, the PRACH configuration of the radio cell contained in asecond broadcast channel signal is a PRACH configuration of thecontrolled master carrier and/or the auxiliary carrier; and when themobile terminal performs uplink synchronization with the base station,

if the PRACH configuration of the radio cell does not include the PRACHconfiguration of the controlled master carrier, and includes the PRACHconfiguration on the auxiliary carrier, then the mobile terminalperforms the uplink synchronization according to the PRACH configurationon the auxiliary carrier; and/or

if the PRACH configuration of the radio cell includes the PRACHconfigurations on the controlled master carrier and on the auxiliarycarrier, then the mobile terminal only performs the uplinksynchronization on the controlled master carrier or on the auxiliarycarrier, or the mobile terminal selects the controlled master carrier orthe auxiliary carrier to perform the uplink synchronization according toa current radio environment.

Preferably, when transmitting data by using the master carrier and/orthe auxiliary carrier, for the downlink transmission on the controllingmaster carrier,

the mobile terminal detects a downlink transmission instruction on theauxiliary carrier and transmits ACK/NACK information of the downlinktransmission; or

the mobile terminal detects the downlink transmission instruction on thecontrolling master carrier, and transmits the ACK/NACK information ofthe downlink transmission on the controlled master carrier.

Preferably, for the downlink transmission on the controlling mastercarrier, when the mobile terminal detects the downlink transmissioninstruction on the auxiliary carrier and transmits the ACK/NACKinformation, a feedback time sequence of the ACK/NACK information isdetermined according to downlink and uplink configurations of theauxiliary carrier; and

when the mobile terminal detects the downlink transmission instructionon the controlling master carrier, and transmits the ACK/NACKinformation on the controlled master carrier, the feedback time sequenceof the ACK/NACK information is determined according to uplink anddownlink configurations of the controlled master carrier.

Preferably, when transmitting data by using the master carrier and/orthe auxiliary carrier, for the downlink transmission on the controlledmaster carrier,

the mobile terminal detects a downlink transmission instruction on theauxiliary carrier and transmits ACK/NACK information of the downlinktransmission; or

the mobile terminal detects the downlink transmission instruction on thecontrolling master carrier, and transmits the ACK/NACK information ofthe downlink transmission on the controlled master carrier; or

the mobile terminal detects the downlink transmission instruction on thecontrolled master carrier and transmits the ACK/NACK information of thedownlink transmission.

Preferably, for the downlink transmission on the controlled mastercarrier, when the mobile terminal detects the downlink transmissioninstruction on the auxiliary carrier and transmits the ACK/NACKinformation, a feedback time sequence of the ACK/NACK information isdetermined according to uplink and downlink configurations of theauxiliary carrier and the controlled master carrier; and

when the mobile terminal detects the downlink transmission instructionon the controlling master carrier, and transmits the ACK/NACKinformation on the controlled master carrier, the feedback time sequenceof the ACK/NACK information is determined according to the downlink anduplink configurations of the controlled master carrier.

Preferably, when transmitting data by using the master carrier and/orthe auxiliary carrier, for the uplink transmission on the controlledmaster carrier,

the mobile terminal detects uplink transmission scheduling on theauxiliary carrier and receives feedback information of the uplinktransmission; and

the mobile terminal receives the uplink transmission scheduling on thecontrolling master carrier and the feedback information of the uplinktransmission.

Preferably, a radio frame structure of the auxiliary carrier includesdownlink sub-frames, uplink sub-frames, and special sub-frames; whereinthe special sub-frames include a downlink time slot, a guard interval,and an uplink time slot, and the guard interval is configured fortransition from the downlink time slot to the uplink time slot.

A mobile terminal in a radio cell includes an auxiliary carrier in a lowfrequency band and at least one master carrier in a high frequency band,wherein the mobile terminal includes: a downlink synchronization unit, aconfiguration information obtaining unit, and a data transmission unit;wherein

the downlink synchronization unit is configured to perform initialdownlink synchronization with a base station of the radio cell by usingthe auxiliary carrier;

the configuration information obtaining unit is configured to obtainconfiguration information of the radio cell; and

the data transmission unit is configured to transmit data by using themaster carrier and/or the auxiliary carrier according to theconfiguration information of the radio cell.

Preferably, the configuration information obtaining unit is furtherconfigured to receive a first broadcast channel signal sent by theauxiliary carrier, obtain the configuration information of the radiocell borne by a first broadcasting channel; and is also configured toread a second broadcast channel from the master carrier according to theconfiguration information of the radio cell borne by the firstbroadcasting channel, and obtain the configuration information of theradio cell borne by the second broadcast channel.

Preferably, the configuration information obtaining unit is configuredto obtain the configuration information of the radio cell according to afirst broadcast channel signal, a public control indication and a secondbroadcast channel signal sent by the auxiliary carrier.

Preferably, the data transmission unit is further configured to receivea public channel signal sent by the auxiliary carrier, and perform thedata transmission according to the public channel signal.

By way of the method provided according to the present application, aradio cell not only includes a master carrier in a high frequency bandbut also includes an auxiliary carrier in a low frequency band, and datatransmission of the mobile terminal is realized by using a low frequencycarrier to support running of a high frequency band cell, with featuresthat a low frequency carrier transmission having a large transmissionscope and having wide coverage, coverage of the whole radio cell isimproved. Besides of these, the method provided according to the presentapplication improves reliability of radio signaling, and improvesperformance of the radio cell, especially performance of a highfrequency band cell.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a schematic diagram of a basic flow of a method for datatransmission of the present application;

FIG. 2 shows an exemplary diagram of Embodiment 1 of the presentapplication;

FIG. 3 shows an exemplary diagram of frame structures of a mastercarrier and an auxiliary carrier according to Embodiment 1 of thepresent application;

FIG. 4 shows an exemplary diagram of frame structures of a controllingmaster carrier, a controlled master carrier and an auxiliary carrieraccording to Embodiment 2 of the present application; and

FIG. 5 shows a schematic diagram of a basic structure of a mobileterminal according to the present application.

MODE FOR THE INVENTION

To make the object, technical means and advantages of the presentapplication clearer, detailed description will be provided incombination with attached drawings in the following.

In a method for data transmission in a radio cell of a mobile terminalaccording to the present application, and in a method for realizing aradio cell based on low frequency auxiliary carriers and master carriersin a high frequency band, a radio cell at least supports two kinds ofcarriers. The first kind of carrier is master carrier, which may be oneor more. A master carrier is a high frequency band carrier, used toprovide downlink data service transmission. Another kind of carrier isauxiliary carrier, and an auxiliary carrier is a low frequency carrier,e.g., a carrier in 700 MHz˜2.6 GHz frequency band currently being usedfor wireless communication. In the present application, a frequency bandcarrier, a frequency band difference between which and the highestfrequency band of low frequency carriers is larger than a presetthreshold is called a high frequency band carrier; the frequency banddifference refers to a result of a high frequency band minus the highestfrequency band of the low frequency carriers.

The low frequency feature of the auxiliary carrier is mainly used torealize coverage of point-to-multi-point cells. Most basically, theauxiliary carrier may be used to bear downlink synchronization channelsand used for a larger range of UEs to perform downlink synchronizationwith a high frequency band cell. Besides of bearing the downlinksynchronization channels, the auxiliary carrier may also be configuredto bear point-to-multi-point downlink data transmission of broadcastchannels and/or public control channels, etc., bear data transmission ofa part of important downlink sharing channels (e.g., signalingtransmission of a control panel), and at the same time may bear datatransmission of a part of or all uplink random access channels, uplinkcontrol channels, and uplink sharing channels. The master carrier ismainly used to realize point-to-point service data transmission, andespecially when a master carrier is a millimeter, broadband and superbroadband service data transmission may be realized.

For a radio frame structure of the carriers, the master carrier adopts acurrent FDD or TDD frame structure defined by the LTE or a newly definedframe structure. The auxiliary carrier adopts a kind of frame structuresimilar to the TDD format frame structure defined by the LTE. That is, aradio frame of an auxiliary carrier includes downlink sub-frames, uplinksub-frames and special sub-frames. A special sub-frame includes adownlink time slot, a guard interval and an uplink time slot. The guardinterval is configured for transition from a downlink time slot to anuplink time slot. The number of downlink sub-frames, uplink frames andspecial sub-frames and their locations may be configured as needed bythe network, e.g., by adopting any of the 7 TDD frame structures definedby the LTE.

Actual transmission points of the master carrier and the auxiliarycarrier may be same or different, and if in the latter case, averagelatency between a transmission point of the master carrier and atransmission point of the auxiliary carrier and a same receiving pointshould be the same or a latency difference between them should be in arange acceptable for a receiver.

Based on the above construction of the radio cell carriers, in thepresent application, a basic method for data transmission in a radiocell of the mobile terminal includes: the mobile terminal achievingdownlink synchronization with the radio cell via the low frequencyauxiliary carrier, and after the mobile terminal achieving the downlinksynchronization with a base station of the radio cell, obtainingconfiguration information of the radio cell, the master carrier and theauxiliary carrier, and transmitting data by using the master carrierand/or the auxiliary carrier according to the correspondingconfiguration information. By using the low frequency feature of theauxiliary carrier to help the radio cell containing the high frequencycarrier to enlarge coverage, the system performance is improved.

The method for data transmission in a radio cell of the mobile terminalwill be described hereinafter based on FIG. 1. As shown in FIG. 1, themethod includes the following process.

At step 101, the mobile terminal uses the auxiliary carrier to realizeinitial downlink synchronization with the base station.

First, the mobile terminal performs downlink synchronization with thebase station. Preferably, the auxiliary carrier may be used on a fixedposition to send a downlink synchronization signal to realize initialdownlink time synchronization between the terminal and the base station.Since the auxiliary carrier is in a low frequency band, therefore thecoverage of point-to-multi-point transmission thereof may be larger, anddownlink synchronization of mobile terminals in a larger range may berealized.

At step 102, the mobile terminal obtains configuration information ofthe radio cell, the master carrier and the auxiliary carrier accordingto broadcast channel signals of the cell.

Broadcast messages of the cell may be borne by using a first broadcastchannel and a second broadcast channel, in which the first broadcastchannel and the second broadcast channel are divided according tocontent that they bear. Preferably, the first broadcast channel may be amaster broadcast channel, bearing master broadcast messages (MasterInformation Block), and the second broadcast channel may be a commonbroadcast channel, bearing common system broadcast messages (SystemInformation Block). The broadcast messages at least include informationsuch as a bandwidth of the ancillary carrier, a frequency of the mastercarrier, a bandwidth of the master carrier, a radio frame structure ofthe master carrier, uplink & downlink cyclic prefix length of the mastercarrier, PRACH resource configurations of the cell, etc. Besides ofthese, other related information may be used to inform the terminal ofsounding reference signal configurations thereof on the master carrier,in which public configurations are included in the broadcast messages,and the dedicated configurations may be obtained from other subsequentmessages.

In the above broadcast signals, the PRACH resource configurations of thecell may be PRACH resource configurations on the master carrier or PRACHresource configurations on the auxiliary carrier.

The broadcast messages are carried by the first broadcast channel signaland the second broadcast channel signal. Preferably, the first broadcastchannel signal may be borne by the auxiliary carrier so as to improvethe coverage of the first broadcast channel signal by using the lowfrequency feature of the auxiliary carrier.

At step 103, the mobile terminal performs data transmission by using themaster carrier and/or the auxiliary carrier according to theconfiguration information obtained from step 102.

Based on the configuration information of the cell and the carriers,information such as the bandwidth, the frame structure, etc. of thecarriers may be determined and may be used to perform data transmission.

When the data transmission is performed, preferably, the auxiliarycarrier may be used to feed back ACK/NACK (Acknowledge/Non-acknowledge)information of the downlink transmission. The ACK/NACK information maybe carried in the uplink control channels or uplink sharing channels inthe auxiliary carrier, and in this case, a time sequence of downlinkHARQ is decided by the frame structure of the auxiliary carrier and theframe structure of one or more carriers where the downlink transmissionis performed.

The auxiliary carrier may be further configured to transmit downlinkdata of the mobile terminal, and the downlink data mainly refers toinformation with a high priority such as high level signaling, etc.

To facilitate understanding of the present application, the abovetechnical solution of the present application will be further describedhereinafter in combination with specific application scenarios. As anexample, the master broadcast channel is the first broadcast channel,and the common broadcast channel is the second broadcast channel.

Application Scenario 1

In the present application scenario, a radio cell A includes more thantwo (including two) carriers, in which one of the carriers is a lowfrequency auxiliary carrier (such as 700 MHz˜2.6 GHz frequency band thatis currently being used for wireless communication), and the others arehigh frequency band carriers.

The low frequency carrier only carries a downlink synchronizationchannel and a master broadcast channel. Time-frequency positions of thedownlink synchronization channel and the master broadcast channel arerelatively fixed on the auxiliary carrier. The downlink synchronizationchannel is configured to synchronize time between the terminal and thecell and search for cells. Messages in the master broadcast channelindicate information such as the bandwidth of the auxiliary carrier, thesystem frame number of the auxiliary carrier, the frequency of themaster carrier, the bandwidth of the master carrier, and the framestructure of the master carrier (TDD or FDD), etc.

A terminal that supports millimeter wave communication, by detecting thedownlink synchronization channel in the frequency band of the auxiliarycarrier, achieves downlink synchronization with the radio cell, and thenby reading the master broadcast messages, the cell configurationinformation including main cell information such as system bandwidth andsystem frame numbers of the auxiliary carrier, the frequency of themaster carrier, the bandwidth of the master carrier, and the framestructure of the master carrier (TDD or FDD) borne on the masterbroadcast channel is obtained. The radio terminal that obtains the aboveinformation may further read common broadcast messages from the mastercarrier, and obtain detailed configuration information of the mastercarrier, e.g., SRS configurations, PRACH configurations, etc.

A terminal that resides in a radio cell A, when there are downlink anduplink service requirements, or when it receives a paging message fromthe base state and the paging message contains an identity of theterminal (UE-Identity), needs to initiate a process of establishing aconnection with the base station. During the process of establishing theconnection, the terminal sends PRACH according to PRACH configurationsof the cell, and carries out receiving and sending of subsequentmessages related to establishing the connection, until the terminalreceives dedicated radio resource configuration information targeted forit. The radio resource configuration information dedicated for theterminal at least includes SRS dedicated configuration information ofthe terminal on the master carrier and on the auxiliary carriers, uplinkcontrol channel dedicated configuration information of the terminal onthe master carrier, and downlink and uplink transmission channeldedicated configuration information of the terminal on the mastercarrier, etc.

The terminal that resides in the radio cell A, when it is in activatedstatus, may send and receive downlink and uplink data over the mastercarrier.

Application Scenario 2

In the present example, as an example, the master carrier is a carrierin the millimeter frequency band, and the corresponding radio cell is amillimeter wave cell. As is shown in FIG. 2, a millimeter wave cellworking in TDD mode supports two carries at the same time, in which themaster carrier is in the millimeter wave frequency band, and theauxiliary carrier is in the low frequency band (e.g., 700 MHz˜2.6 GHzfrequency band that is currently being used for wireless communication)

The radio frame structure on the master carrier is TDD mode. That is, aradio frame is divided into multiple sub-frames by time, and accordingto different configurations, these sub-frames are divided into downlinksub-frames, uplink sub-frames and special sub-frames. An example of thisis shown in FIG. 3. an uplink time slot of the uplink sub-frames or thespecial sub-frames of the master carrier should be at least configuredwith SRS resources, and may be configured with PRACH resources.

The radio frame structure of the auxiliary carrier is also TDD mode, andratios occupied by the downlink sub-frames, the uplink sub-frames, andthe special sub-frames in the radio frame structure of the auxiliarycarrier and their positions in the radio frame may be different fromthat of the master carrier.

The auxiliary carrier bears a synchronization channel and a masterbroadcast message on determined positions, and in addition, it may bearcommon system messages. The synchronization channel is used for downlinktime synchronization of the terminal and the cell and searching forcells. The master broadcast message and the common system messages areused to indicate information such as the bandwidth of the auxiliarycarrier, the frame number of the auxiliary carrier, the frequency of themain frequency, the bandwidth of the master carrier, the TDDconfigurations of the master carrier and the auxiliary carrier, and SRSpublic configurations on the master carrier, etc., the PRACHconfigurations on the master carrier (given that there are PRACHresources on the master carrier) and on the auxiliary carrier. PRACHresources may be configured for the auxiliary carrier to perform uplinksynchronization between the terminal and the base station.

The terminal that supports the millimeter wave communication, bydetecting the synchronization channel on the auxiliary carrier, achievesthe downlink synchronization with the millimeter wave cell, and byreading the master broadcast message, obtains main cell information suchas a system bandwidth and a system frame number of the auxiliarycarrier, and then, reads some common broadcast messages to obtain commonsystem messages carried in the auxiliary carrier, including: thefrequency of master carrier, the bandwidth of master carrier, the TDDconfigurations of the master carrier and the auxiliary carrier, and SRSpublic configuration information on the master carrier, PRACHconfigurations on the master carrier (if there are PRACH resources onthe master carrier) and on the auxiliary carrier.

The terminal that resides in the millimeter wave cell C, when it is inidle status, may only monitor a downlink control channel on theauxiliary carrier, and obtain paging messages and broadcast messages.

The terminal that resides in the millimeter wave cell C, when there aredownlink and uplink service requirements, or receives a paging messagefrom the base station, and the paging message contains an identity ofthe terminal (UE-Identity), needs to initiate a process of establishinga connection with the base station. During initiating the process ofestablishing the connection, the terminal sends PRACH according to thePRACH configurations of the cell, and carries out sending and receivingof subsequent messages related to establishing the connection on theauxiliary carrier or on the master carrier, until wireless resourceconfiguration information dedicated for the terminal is received. Thewireless resource configuration information dedicated for the terminalmay at least contain SRS dedicated configuration messages on the mastercarrier and the auxiliary carrier, the uplink control channel dedicatedconfiguration information of the terminal on the master carrier and onthe auxiliary carrier of the terminal, and the downlink and uplinkdedicated configuration information of the terminal on the mastercarrier and on the auxiliary carrier.

The PRACH configurations of the cell may be PRACH configurations on themaster carrier and/or PRACH configurations on the auxiliary carrier. Ifa purpose of the PRACH is to initiate establishment of an initialconnection, then a carrier that sends and receives the messages relatedto the establishment of the connection is the same with that where thePRACH is located. When the mobile terminal sends the PRACH, if there areno PRACH configurations on the master carrier, and there are PRACHconfigurations on the auxiliary carrier, then the mobile terminalinitiates the PRACH on the PRACH resources of the auxiliary carrier; andif PRACH configurations exist in both of the master carrier and theauxiliary, then the terminal may only initiate PRACH on the auxiliarycarrier, or only initiate PRACH on the master carrier, or the locationof initiating the PRACH may be decided according to a current radioenvironment (e.g., path loss). Preferably, for a terminal where theradio environment is relatively good (e.g., the radio environment issuperior than a threshold), it may select the master carrier to initiatethe PRACH, or otherwise, it may select the auxiliary carrier to initiatethe PRACH; and if there are PRACH configurations on the master carrier,and there are no PRACH configurations on the auxiliary carrier, then themobile terminal initiates the PRACH on the PRACH resources of the mastercarrier.

The terminal that resides in the millimeter wave cell C, when it is inactivated status, may receive downlink data from the master carrier andthe auxiliary carrier at the same time. For downlink transmission on theauxiliary carrier, the terminal detects a downlink transmissioninstruction targeted for the auxiliary carrier on the auxiliary carrier,and feeds back ACK/NACK information of the downlink transmission on theauxiliary carrier. For the downlink transmission on the master carrier,the terminal may detect a downlink transmission instruction targeted forthe master carrier on the auxiliary carrier, and feed back ACK/NACKinformation of the downlink transmission by the auxiliary carrier. Inthis case, a feedback time sequence of the ACK/NACK of the downlinktransmission may be decided by the uplink and downlink configurations ofthe master carrier and the auxiliary carrier; or the terminal may alsodetect the downlink transmission instruction targeted for the mastercarrier on the master carrier, and feed back the ACK/NACK of thedownlink transmission by the master carrier.

When uplink data transmission is performed, the terminal may transmituplink data on the master carrier and on the auxiliary carrier at thesame time. For uplink transmission on the auxiliary carrier, theterminal receives uplink transmission scheduling targeted for theauxiliary carrier on the auxiliary carrier and receives uplinktransmission feedback on the auxiliary carrier. For the uplinktransmission on the master carrier, the terminal may receive uplinktransmission scheduling targeted for the master carrier from theauxiliary carrier and receive the uplink transmission feedback from theauxiliary carrier. In this case, the time sequence of the uplinktransmission is decided by the uplink and downlink configurations of themaster carrier and the auxiliary carrier; or the terminal may receiveuplink transmission scheduling targeted for the master carrier andreceive uplink transmission feedback from the master carrier.

Application Scenario 3

As is shown in FIG. 4, a millimeter wave cell that works in TDD modesupports three carriers at the same time, in which two master carriersare in millimeter wave frequency band, and one auxiliary carrier is inlow frequency band (e.g., 700 MHz˜2.6 GHz frequency band currently beingused for wireless communication).

The radio frame structure on the master carrier is a hybrid duplex mode.That is, one of the master carriers is called a controlling mastercarrier. A radio frame structure of the controlling master carriercontains a “configurable sub-frame”. The “configurable sub-frame”consists of a special downlink time slot, a guard time slot, and anuplink pilot time slot, and the total length thereof is a sub-frame, andother sub-frames in the radio frame are downlink sub-frames. The uplinkpilot time slot in the configurable sub-frame of the controlling mastercarrier is at least configured with SRS resources.

Another master carrier is call controlled master carrier, and a radioframe structure of the controlled master carrier may be configured as afull uplink sub-frame carrier, or an uplink and downlink time divisionmultiplex carrier: when the controlled master carrier is all uplink, itconstitutes the traditional FDD mode to perform communication togetherwith the controlling master carrier; when the controlled master carrieris an uplink and downlink time division multiplex carrier, the downlinkon the controlling master carrier cooperates the uplink on thecontrolled master carrier to perform unequal-proportion FDD modecommunication, and/or the downlink on the controlling master carriercooperates with the uplink on the controlled master carrier to performthe traditional TDD mode communication; the uplink pilot time slot ofthe uplink sub-frame or the special sub-frame of the controlled carrieris at least configured with SRS configurations, and may be configuredwith PRACH configurations. The radio frame structure and communicationmode of the controlling master carrier and the controlled master carriermay be realized in any way that meets the above rules, e.g., in a way asdescribed in the application filed on Aug. 9, 2013, with the applicationnumber being CN201310347085.6.

The radio frame structure of the auxiliary carrier is TDD mode, and theproportions of the uplink sub-frames, downlink sub-frames, and specialsub-frames in the radio frame structure of the auxiliary carrier may bedifferent from that in the master carrier. The auxiliary carrier bears asynchronization channel and a master broadcast message on specificpositions. In addition, it may bear a common system message, and thesynchronization channel may be used to perform downlink timesynchronization between the terminal and the cell, and search for cells.The master broadcast message and the common system message areconfigured to indicate information such as a bandwidth of the auxiliarycarrier, a system frame number of the auxiliary carrier, a frequency ofthe master carrier, a bandwidth of the master carrier, TDDconfigurations of the master carrier and the auxiliary carrier, andpublic configurations of the SRS on the master carrier, the PRACHconfigurations on the master carrier (if there are PRACH resourcesexisting on the master carrier) and on the auxiliary carrier. Theauxiliary carrier should be configured with the PRACH resources, usedfor uplink synchronization between the terminal and the base station.

The terminal that supports the millimeter wave communication, whenachieving the downlink synchronization and obtaining the cellconfiguration information, achieves the downlink synchronization withthe millimeter wave cell by detecting the downlink synchronizationchannel on the frequency band of the auxiliary carrier, then obtainsmain cell information such as a system bandwidth and a system framenumber of the auxiliary carrier by reading the master broadcast message,then reads a serial of common broadcast messages, indicating informationsuch as the frequency of the master carrier, the bandwidth of the mastercarrier, TDD configurations of the controlled master carrier and theauxiliary carrier, the SRS public configurations on the controllingmaster carrier and on the controlled master carrier, the PRACHconfigurations on the controlled master carrier (if there are PRACHresources existing on the master carrier) and on the auxiliary carrier,etc.

uplink and downlink synchronization and cell configuration information,detects downlink synchronization channels on the frequency band of theauxiliary carrier, achieves downlink synchronization with the millimeterwave cell, then then by reading the master broadcast message, obtainscell information such as system bandwidth of the auxiliary carrier andsystem frame number. Then, it obtains a series of common broadcastmessages, obtains common system messages carried in the auxiliarycarrier, instructs a frequency of the master carrier, the bandwidth ofthe master carrier, and the TDD configurations of the controlled mastercarrier and the auxiliary carrier, and the public configurations of SRRof the controlling master carrier and the controlled master carrier, andcell configuration information such as controlled master carrier (ifthere are PRACH resources existing in the master carrier) and the PRACHconfigurations on the auxiliary carrier.

The terminal that resides in the millimeter wave cell C, when in idlestatus, may monitor the downlink control channel on the auxiliarycarrier to obtain paging messages and broadcast messages.

The terminal that resides in the millimeter wave cell C, when it hasuplink and downlink service needs, or when it receives a paging messagefrom the base station, and the paging message contains an identity ofthe terminal (UE-Identity), needs to initiate establishing theconnection with the base station. During the process of initiatingestablishing the connection, the mobile terminal sends PRACH accordingto the PRACH configurations of the cell, and carries out receiving andsending of messages related to subsequent connection establishment,until specific radio resource configuration information targeted for theterminal is received. The radio resource configuration informationtargeted for the terminal at least contains SRS specific configurationinformation of the terminal on the controlling master carrier, on thecontrolled master carrier, and on the auxiliary carrier, the uplinkcontrol channel specific configuration information of the terminal onthe controlled master carrier and on the auxiliary carrier, the specificconfiguration information of the downlink and uplink transmissionchannels of the terminal on the controlled master carrier and on theauxiliary carrier, etc.

The PRACH configurations of the cell may be PRACH configurations on thecontrolled master carrier and/or PRACH configurations on the auxiliarycarrier. When the mobile terminal sends the PRACH, if there are no PRACHconfigurations on the controlled master carrier, there are PRACHconfigurations on the auxiliary carrier, then the mobile terminalinitiates PRACH on the PRACH resources of the auxiliary carrier; and ifthe PRACH configurations exist both on the controlled master carrier andon the auxiliary carrier, then the terminal may only initiate the PRACHon the auxiliary carrier, or initiate the PRACH on the controlled mastercarrier, or it decides the location to initiate the PRACH according to acurrent radio environment (e.g., path loss). Preferably, for a terminalwith a good radio environment (e.g., the radio environment is superiorthan a predefined threshold), then the controlled master carrier may beselected to initiate the PRACH, or otherwise, the auxiliary carrier maybe selected to initiate the PRACH; and if the PRACH configurations existin the controlled master carrier, and there are no PRACH configurationson the auxiliary carrier, then the mobile terminal initiates the PRACHon the PRACH resources of the controlled master carrier.

The terminal that resides in the millimeter wave cell C, when inactivated status, may receive downlink data from the controlling mastercarrier, the controlled master carrier and the auxiliary carrier. Fordownlink transmission on the auxiliary carrier, the terminal detects adownlink transmission instruction dedicated for the auxiliary carrier onthe auxiliary carrier, and feeds back ACK/NACK information of thedownlink transmission on the auxiliary carrier. For the downlinktransmission on the controlling master carrier, the terminal may detecta downlink transmission instruction dedicated for the controlling mastercarrier, and feed back the ACK/NACK of the downlink transmission byusing the auxiliary carrier. In this case, an ACK/NACK feedback timesequence of the downlink transmission may be decided by the uplink anddownlink configurations of the auxiliary carrier. Or, the terminal maydetect a downlink transmission instruction dedicated for the controllingmaster carrier on the controlling master carrier, and feed back theACK/NACK of the downlink transmission by using the controlled mastercarrier. In this case, the ACK/NACK feedback time sequence of thedownlink transmission is decided by the uplink and downlinkconfigurations of the controlled master carrier. For downlinktransmission on the controlled master carrier, the terminal may detect adownlink transmission instruction dedicated for the controlled mastercarrier on the auxiliary carrier, and feed back the ACK/NACK of thedownlink transmission. In this case, the ACK/NACK feedback time sequenceof the downlink transmission may be decided by the uplink and downlinkconfigurations on the auxiliary carrier and on the controlled mastercarrier. Or, the terminal may also detect the downlink transmissioninstruction dedicated for the controlled master carrier on thecontrolling master carrier and feed back the ACK/NACK of the downlinktransmission by using the controlled master carrier. In this case, theACK/NACK feedback time sequence of the downlink transmission is decidedby the uplink and downlink transmission configurations of the controlledmaster carrier. Or, the terminal may detect the downlink transmissioninstruction dedicated for the controlled master carrier on thecontrolled master carrier, and feed back the ACK/NACK of the downlinktransmission via the controlled master carrier. In this case, theACK/NACK feedback time sequence of the downlink transmission is decidedby the downlink and uplink configurations of the controlled mastercarrier.

When performing the uplink data transmission, the terminal may send theuplink data on the controlled master carrier and on the auxiliarycarrier. For uplink transmission on the auxiliary carrier, the terminalreceives the uplink transmission scheduling dedicated for the auxiliarycarrier, and receives the uplink transmission feedback on the auxiliarycarrier. For the uplink transmission of the controlled master carrier,the terminal may receive the uplink transmission scheduling dedicatedfor the master carrier, and receive the uplink transmission feedback onthe auxiliary carrier. In this case, the time sequence of the uplinktransmission is decided by the uplink and downlink configurations of theauxiliary carrier and the controlled master carrier. Or the terminal mayreceive uplink transmission scheduling dedicated for the controlledmaster carrier on the controlling master carrier, and receive the uplinktransmission feedback on the controlling master carrier. In this case,the time sequence of the uplink transmission may be decided by theuplink and downlink configurations of the controlled master carrier.

In the above Scenario 2, a controlling master carrier and a controlledmaster carrier are used as example for illustration. In fact, there maybe a plurality of controlling master carriers and a plurality ofcontrolled master carriers, in which each of the controlling mastercarriers and the controlled master carriers may be processed in a sameway as described in the above, which will not be elaborated herein.

The method for data transmission in a radio cell of the mobile terminalaccording to the present application is described as above. The presentapplication also provides a mobile terminal, when it resides in a cellincludes a low frequency band carrier and a high frequency band carrier,is configured to implement the above data transmission method. FIG. 5shows a basic structure of the mobile terminal according to the presentapplication. As shown in FIG. 5, the mobile terminal includes: adownlink synchronization unit, a configuration information obtainingunit and a data transmission unit.

The downlink synchronization unit is configured to realize initialdownlink synchronization with a base station of the radio cell by usinga downlink synchronization signal sent by the auxiliary carrier. Theconfiguration information obtaining unit is configured to obtainconfiguration information of the radio cell, the master carrier and theauxiliary carrier. The data transmission unit is configured to transmitdata by using the master carrier and/or the auxiliary carrier accordingto the configuration information of the radio cell, the master carrierand the auxiliary carrier.

Preferably, the auxiliary carrier may be used to transmit a downlinksynchronization signal, a broadcast channel signal and/or a publiccontrol channel signal. When the radio cell transmits the downlinksynchronization signal by using the auxiliary carrier, the downlinksynchronization unit is further configured to receive the downlinksynchronization signal sent by the auxiliary carrier, and performs theinitial downlink synchronization according to the downlinksynchronization signal. When the radio cell transmits the broadcastchannel signal by using the auxiliary carrier, there may be two specifictransmission ways:

1) the configuration information obtaining unit is further configured toreceive the master broadcast channel signal sent from the auxiliarycarrier, obtain configuration information of the radio cell borne by themaster broadcaster channel; and is also configured to read the commonbroadcast channel from the master carrier according to the configurationinformation of the radio cell borne by the master broadcast channel, andobtain the configuration information of the radio cell borne by thecommon broadcast channel; and

2) the configuration information obtaining unit is further configured toobtain the configuration information of the radio cell according to themaster broadcast channel signal, the public control channel indication,and the common broadcast channel signal.

When the radio cell sends the public control signals by using theauxiliary carrier, the data transmission unit is further configured toreceive the public channel signal sent by the auxiliary carrier, and isfurther configured to transmit data according to the public channelsignals.

In the data transmission method provided according to the presentapplication, large point-to-multi-point coverage may be realized byusing the auxiliary carrier so as to make up the transmission distancedefect of the millimeter frequency band carrier on thepoint-to-multi-point data transmission, so as to improve the coverage ofthe millimeter cell and the transmission performance.

What described above are only preferable embodiments of the presentinvention, and are not to limit the present invention, anymodifications, equivalent replacements, improvements, etc. made withinthe spirit and principle of the present invention should be contained inthe scope of the present invention.

The invention claimed is:
 1. A method for data transmission in a radiocell of a mobile terminal, wherein the radio cell comprises an auxiliarycarrier in a low frequency band and at least one master carrier in ahigh frequency band, the method comprising: achieving, by the mobileterminal, downlink synchronization with the radio cell through theauxiliary carrier in the low frequency band; obtaining, by the mobileterminal, configuration information of a master carrier and theauxiliary carrier of the radio cell, the configuration informationcomprising a radio frame structure of the master carrier; transmitting,by the mobile terminal, data using the master carrier or the auxiliarycarrier according to the configuration information; and if a downlinktransmission instruction for a downlink transmission on the mastercarrier is received on the auxiliary carrier, transmitting, on theauxiliary carrier, ACK/NACK information regarding the downlinktransmission, wherein, the high frequency band is a millimeter wavefrequency band and the low frequency band is in between 700 MHz and 2.6GHz, wherein when a public control channel exists on the auxiliarycarrier and does not exist on the master carrier, a downlink controlchannel only on the auxiliary carrier is monitored by the mobileterminal to obtain a paging message or a broadcast message.
 2. Themethod according to claim 1, wherein the auxiliary carrier is configuredto bear a downlink synchronization channel and a first broadcastingchannel, wherein achieving the downlink synchronization with the radiocell through the auxiliary carrier in the low frequency band comprises:achieving initial downlink synchronization with a base station of theradio cell by using a downlink synchronization signal sent by theauxiliary carrier, wherein obtaining the configuration information ofthe radio cell comprises: the mobile terminal obtaining configurationinformation of the radio cell borne on a first broadcast channelaccording to a first broadcast channel signal sent by the auxiliarycarrier; the mobile terminal reading a second broadcast channel from themaster carrier according to the configuration information of the radiocell borne on the first broadcast channel; and obtaining configurationinformation of the radio cell borne on the second broadcast channel. 3.The method according to claim 2, wherein the configuration informationof the radio cell borne on the first broadcast channel comprises atleast one of information on a bandwidth of the auxiliary carrier, asystem frame number of the auxiliary carrier, a frequency of the mastercarrier, a bandwidth of the master carrier, and downlink cyclic prefixlength of the master carrier, wherein the configuration information ofthe radio cell borne on the second broadcast channel comprises a publicconfiguration of a sounding reference signal SRS on the master carrierand an uplink random access PRACH configuration of the radio cell, andwherein the PRACH configuration of the radio cell comprises PRACHconfiguration information on the master carrier or on the auxiliarycarrier.
 4. The method according to claim 1, wherein the auxiliarycarrier is configured to bear a downlink synchronization channel, afirst broadcast channel, the public control channel and a secondbroadcast channel; wherein achieving the downlink synchronization withthe radio cell through the auxiliary carrier in the low frequency bandcomprises: the mobile terminal carrying out initial downlinksynchronization with a base station of the radio cell by using adownlink synchronization signal sent by the auxiliary carrier; andwherein obtaining the configuration information of the radio cellcomprises: the mobile terminal obtaining the configuration informationof the radio cell according to a first broadcast channel signal, apublic control channel indication and a second broadcast channel signal.5. The method according to claim 4, wherein the configurationinformation of the radio cell comprises at least one of a bandwidth ofthe auxiliary carrier, a system frame number of the auxiliary carrier, afrequency of the master carrier, a bandwidth of the master carrier, apublic configuration of a sounding reference signal SRS on the mastercarrier and an uplink random access PRACH configuration of the radiocell, and wherein the PRACH configuration of the radio cell comprisesPRACH configuration information on the master carrier or on theauxiliary carrier.
 6. The method according to claim 2, wherein the firstbroadcast channel is a master broadcast channel, and the secondbroadcast channel is a common broadcast channel.
 7. The method accordingto claim 3, wherein, when the mobile terminal transmits data by usingthe master carrier or the auxiliary carrier, a process of establishing aconnection with the base station initiated by the mobile terminalcomprises: the mobile terminal performing an uplink synchronization withthe base station by using the PRACH configuration of the radio cell, andcarrying out sending and receiving of related messages during theprocess of establishing the connection, until receiving radio resourceconfiguration information specific for the mobile terminal.
 8. Themethod according to claim 7, wherein the radio resource configurationinformation specific for the mobile terminal comprises at least one ofSRS specific configuration information of the mobile terminal on themaster carrier and on the auxiliary carrier, uplink control channelspecific configuration information of the mobile terminal on the mastercarrier and on the auxiliary carrier, and uplink and downlinktransmission channel specific configuration information of the mobileterminal on the master carrier and on the auxiliary carrier.
 9. Themethod according to claim 7, wherein the mobile terminal performing theuplink synchronization with the base station by using the PRACHconfiguration of the radio cell comprises: if the PRACH configuration ofthe radio cell does not comprise a PRACH configuration on the mastercarrier and comprises a PRACH configuration on the auxiliary carrier,then the mobile terminal performs the uplink synchronization accordingto the PRACH configurations on the auxiliary carrier, or if the PRACHconfiguration of the radio cell comprises the PRACH configurations onthe master carrier and on the auxiliary carrier, then the mobileterminal only performs the uplink synchronization on the master carrieror on the auxiliary carrier, or the mobile terminal selects the mastercarrier or the auxiliary carrier to perform the uplink synchronizationaccording to a current radio environment.
 10. The method according toclaim 9, wherein the mobile terminal selecting the master carrier or theauxiliary carrier to perform the uplink synchronization according to thecurrent radio environment comprises: if the current radio environment issuperior than a predefined threshold, then the mobile terminal selectingthe master carrier to perform the uplink synchronization, or otherwise,the mobile terminal selecting the auxiliary carrier to perform theuplink synchronization.
 11. The method according to claim 9, wherein,during a process of establishing an initial connection, a carrier thatreceives and sends messages related to the process of establishing theconnection matches a carrier where a PRACH is located.
 12. The methodaccording to claim 1, wherein, when transmitting data by using themaster carrier or the auxiliary carrier, for downlink transmission onthe auxiliary carrier, the mobile terminal detects a downlinktransmission instruction on the auxiliary carrier and transmits ACK/NACKinformation of the downlink transmission.
 13. The method according toclaim 1, wherein, a feedback time sequence of the ACK/NACK informationis determined according to downlink and uplink configurations of themaster carrier and the auxiliary carrier.
 14. The method according toclaim 1, wherein when transmitting data by using the master carrier orthe auxiliary carrier, for an uplink transmission on the auxiliarycarrier, the mobile terminal receives uplink transmission scheduling andreceives feedback information of the uplink transmission on theauxiliary carrier; or for the uplink transmission on the master carrier,the mobile terminal receives the uplink transmission scheduling and thefeedback information of the uplink transmission on the master carrier.15. The method according to claim 2, wherein the at least one mastercarrier of the radio cell comprises at least one first master carrierand at least one second master carrier, wherein a radio frame structureof the at least one first master carrier comprises downlink sub-framesand configurable sub-frames, wherein the configurable sub-framescomprising at least one of a special downlink time slot, a guard timeslot, and an uplink pilot time slot; and wherein all sub-frames in aradio frame structure of the at least one second master carrier areuplink sub-frames, or the at least one second master carrier has adownlink and uplink time division duplex radio frame structure.
 16. Themethod according to claim 15, wherein a PRACH configuration of the radiocell contained in a second broadcast channel signal is a PRACHconfiguration of the at least one second master carrier or the auxiliarycarrier, wherein when the mobile terminal performs uplinksynchronization with the base station, if the PRACH configuration of theradio cell does not include the PRACH configuration of the at least onesecond master carrier, and includes the PRACH configuration on theauxiliary carrier, then the mobile terminal performs the uplinksynchronization according to the PRACH configuration on the auxiliarycarrier; or if the PRACH configuration of the radio cell includes thePRACH configurations on the at least one second master carrier and onthe auxiliary carrier, then the mobile terminal only performs the uplinksynchronization on the at least one second master carrier or on theauxiliary carrier, or the mobile terminal selects the at least onesecond master carrier or the auxiliary carrier to perform the uplinksynchronization according to a current radio environment.
 17. The methodaccording to claim 15, wherein when transmitting data by using themaster carrier or the auxiliary carrier, for downlink transmission onthe at least one first master carrier, the mobile terminal detects adownlink transmission instruction on the auxiliary carrier and transmitsACK/NACK information of the downlink transmission; or the mobileterminal detects the downlink transmission instruction on the at leastone first master carrier, and transmits the ACK/NACK information of thedownlink transmission on the at least one second master carrier.